1. Field of the Invention
The present invention relates to an airtight package for sealing a device, such as a MEMS, in an airtight manner under vacuum pressure.
2. Description of the Related Art
Jpn. Pat. Appln. KOKAI Publication No. 2004-160648, for example, has proposed a package for sealing a device, such as a micro electro mechanical system (MEMS), in an airtight manner, and a sealing method for the package. The technique of Jpn. Pat. Appln. KOKAI Publication No. 2004-160648 will now be described briefly with reference to FIG. 11.
In FIG. 11, a semiconductor substrate 130 with a large number of MEMSs formed thereon, and a lid member 110 formed of glass with a getter attached to cavity are opposed to each other in a vacuum chamber 120. Subsequently, an inactive gas is supplied into the vacuum chamber 120 through a gas introducing section 140 communicating therewith. At this time, the gas introducing section 140 and a gas exhausting section 150 are controlled so that the vacuum chamber 120 can be kept at a preset vacuum degree. After the vacuum chamber 120 is reliably set at the vacuum degree, a high voltage is applied to the lid member 110 while the lid member 110 is heated, thereby bonding the lid member 110 to the semiconductor substrate 130.
This airtight sealing method enables the degree of vacuum to be adjusted to a desired value, and is superior in that an initial degree of vacuum can be maintained even after a preset time elapses.